In Donut County, players move a hole in the ground around the screen, swallowing up anything it touches. The more the hole "eats," the bigger it gets.

It's got a charming, papercraft-like art style featuring characters like a duck riding a scooter and a chatty family of raccoons.

Hole.io, published by the Paris-based mobile studio Voodoo, also features a hole in the ground that gets bigger as it swallows more objects. Gone are the raccoon family and storyline, replaced by a more generic cityscape setting.

In a tweet, Esposito described Hole.io as a "cheap clone," its core gameplay mechanic seemingly lifted from trailers for Donut County.

"I was really concerned, because my game is the exact same concept. It's a hole in the ground, you move it around, stuff falls in and it gets bigger — which I thought was such a wacky idea that no-one else would use it," he said.

Ben Esposito has been working on his upcoming game, Donut County, for the last 5 years. He plans to release it by the end of 2018. (Submitted by Ben Esposito)

In a statement, a representative for Voodoo told Day 6 that "our developers, whether internal or external … freely interpret existing gameplays as it is the custom throughout the profession where all developers feed off each other's creations.

"For instance, Donut County and Hole.io are two games with similar gameplay but with different interpretations that each bring a unique game experience," the statement said.

D'Anastasio said Voodoo has "put out a number of games that resemble, in pretty significant ways, other indie developers' games as well."

She explained that game designers and studios have historically used pre-existing ideas or concepts to make new ones all the time. Nintendo owns the likeness of Mario, for example, but not the idea of running and jumping on a two-dimensional plane.

That practice often leads to entire new genres of games growing out of a single game's new idea.

Who owns the 'idea' behind a game?

The fine line lies in the distinction between a game that's merely "inspired by" a previous game, and a game that's an outright copy.

Games reporter Cecilia D'Anastasio says independent game developers rarely have the time and money required to take another company that they believe copied their games to court. (Submitted by Cecilia D'Anastasio)

"It's easy enough to spot literal copying – the copy or elements of the copy are exactly the same as the original," Mark Edwards, an Ontario-based lawyer with expertise in digital and traditional entertainment industries, told Day 6.

"But what if the game is not literally a copy, but simply uses a feature or combination of features of the original game?"

He cited a 2013 decision involving a television cartoon, where the Supreme Court of Canada took a "holistic" approach that considered "the cumulative effect of the features copied from the work" in the case.

"In the case of Donut County and Hole.io, it is possible that the growing hole feature of Donut County is itself so distinctive and original that this feature alone constitutes a substantial part of the original game," he said.

Clone wars

D'Anastasio pointed to Infinite Golf, which resembles Vancouver-based Pirate Games' 2014 hit Desert Golfing, as well as The Fish Master, which plays similarly to Ridiculous Fishing by Vlambeer.

Like Donut County, a clone of Ridiculous Fishing called Ninja Fishing appeared in app stores before Ridiculous Fishing itself was finished.

"It almost killed the company right there and then," Vlambeer's Rami Ismail told Kotaku.

"Independent creators come from a place of passion," he said, "and nothing will destroy that passion like feeling like you've been taken advantage of — and nothing will kill the drive to be creative faster than seeing someone else treat it as a cynical cash-grab."

Left: Ridiculous Fishing, by Vlambeer. Right: Ninja Fishing, by Gamenauts, which Vlambeer alleges is a clone of their game. (Vlambeer, Gamenauts)

The story pointed to Voodoo's own website, which proclaims: "We are experts at buying cheap installs in big numbers, thanks to our mobile growth team."

Goldman Sachs invest in Hole.io makers

In both Canada and the United States, taking a clone to court is often too costly for small businesses like indie game makers.

"It takes a lot of energy, takes a lot of time and it takes a lot of money. And when you're putting in 40, 50, 60, 70 hours a week trying to not just put out a video game, but generate hype for an upcoming video game, I can't imagine anything less appealing than pursuing a lawsuit," said D'Anastasio.

The prospect of facing off against a company like Voodoo in court could be especially daunting. It recently received a $200 million US investment from Goldman Sachs' private equity fund, aiming to double its staff to 150 this year.

Donut County features a storyline and colourful cast of characters including a family of raccoons. Hole.io doesn't have a story, but includes a cityscape setting and online competitive multiplayer matches. (Ben Esposito/Annapurna Interactive)

As for Donut County, Esposito expressed a degree of resignation at the Hole.io situation while remaining hopeful for his own game's fortunes.

"I feel like I'm kind of I have to come to terms with it and I have to just relax and say, 'Look, this is just a hazard of making something new," he said.

"It's a hazard of being small and needing exposure to get people to buy your art."